USA has been far better for over 100 years. But that had to end at some point. So now we're seeing it end.
100 years?
In the 1920s and 1930s the US had:
- Forced labor
- Peonage
- Debt servitude
- Jim crow laws
The 19th amendment was ratified in 1920, so that barely missed the cutoff.
The US has not been some beacon of moral righteousness for the majority of its existence.
A hundred years? Maybe after WW2. The Great Depression was pretty rough over there.
Far better than who?
Nah, there was just more economic activity to draw people in. By every other measure it’s been more hostile than average.
But you are right that it is ending, just wrong about what: it’s the high economic activity that attracted people which is disappearing thanks to the same people that hate migrants.
It did not "have" to end, it's merely a political choice by one political faction being forced upon the entire nation.